This invention relates to an apparatus and method for reducing pollutants discharging from the exhaust of an internal combustion engine. In one of its aspects this invention relates to controlling the temperature within a catalytic reforming bed to maintain an efficient operating temperature range for the reforming reaction. In another of its aspects this invention relates to the continuous efficient operation of an apparatus which reduces the pollutants discharging from the exhaust of an internal combustion engine even during periods of start-up and engine idling.
U.S. Pat. No. 3,717,129, incorporated herein by reference, sets forth an apparatus and method for passing hydrocarbon fuel for an engine and water through a catalytic bed, increasing the temperature of the water and fuel in contact with the catalytic bed by indirect heat exchange with exhaust gases from the engine, steam-reforming the fuel, and thereafter passing the reformed fuel to the engine for operating the engine with reduced pollutants in the exhaust of the engine. It has been found in operation by the method and apparatus of that patent that during periods of engine operation in which there is a low output of heat of combustion or in which the engine block is being warmed there can be insufficient heat generated to raise the temperature of the reforming catalyst bed to operating conditions and to maintain an efficient operating temperature level. The present invention provides an apparatus and method by which the efficient operating temperature of the reforming catalyst bed can be maintained. In one embodiment of the invention a method and apparatus is provided for utilizing heat generated in the engine block to provide preheating of the hydrocarbon fuel and water being fed into the catalytic bed thereby decreasing the amount of heat input to the catalytic bed by indirect heat exchange with the exhaust gases or by combustion within the catalytic bed to maintain an efficient operating temperature.
It is, therefore, an object of this invention to provide a method and apparatus for maintaining an efficient operating temperature in the catalytic reforming bed of an apparatus reforming a high energy fuel whch is thereafter used in operating an engine for reducing the amount of pollutant material in the exhaust discharging from said engine.
Other aspects, objects, and advantages of the present invention will become apparent from a study of the disclosure, the appended claims, and the drawing.